Best way to automatically assign child IP addresses the correct subnet mask.

[mattg66]

I have a parent prefix 192.168.0.0/24 for example, i would like only IP Addresses with /31 to be allowed inside. When i reserve an IP address, the subnet mask of the IP address is automatically created as a /24. Is there a way to have this automatically be set to /31 as I would like this prefix to act as a container for my point to point IP addresses?

Many thanks